“Propositions are truth-functions of elementary propositions. (An elementary proposition is a truth-function of itself.) (5)”

5.5571
Original German: Wenn ich die Elementarsätze nicht a priori angeben kann, dann muss es zu offenbarem Unsinn führen, sie angeben zu wollen.
1920s, Tractatus Logico-Philosophicus (1922)

Certain, possible, impossible: here we have the first indication of the scale that we need in the theory of probability.
4.464
Original German: Die Wahrheit der Tautologie ist gewiss, des Satzes möglich, der Kontradiktion unmöglich
Source: 1920s, Tractatus Logico-Philosophicus (1922)

Language as Conspiracy, p. 277
Everything Is Under Control (1998)
Context: You need the "is of identity" to describe conspiracy theories. Korzybski would say that proves that illusions, delusions, and "mental" illnesses require the "is" to perpetuate them. (He often said, "Isness is an illness.")
Korzybski also popularized the idea that most sentences, especially the sentences that people quarrel over or even go to war over, do not rank as propositions in the logical sense, but belong to the category that Bertrand Russell called propositional functions. They do not have one meaning, as a proposition in logic should have; they have several meanings, like an algebraic function.

Space, Time and Gravitation (1920)

Source: Allgemeine Erkenntnislehre, 1925, p. 157 ; As cited in: Uebel (2012:78)

" Economic Myths and Public Opinion https://miltonfriedman.hoover.org/friedman_images/Collections/2016c21/AmSpectator_01_1976.pdf” The Alternative: An American Spectator vol. 9, no. 4, (January 1976) pp. 5-9, Reprinted in Bright Promises, Dismal Performance: An Economist’s Protest, New York: Harcourt Brace Jovanovich (1983) pp. 60-75

Source: Carnap’s intellectual biography (1963), p. 62

Rudolf Carnap (1935) Philosophy and Logical Syntax. p. 9-10

4.442
Original German: Ein Satz kann unmöglich von sich selbst aussagen, dass er wahr ist.
1920s, Tractatus Logico-Philosophicus (1922)